Traditionally, penetration of an invasive medical device, such as a needle or catheter tubing, through skin tissue to reach the vein during needle or catheter insertion is invisible to clinicians. For this reason, clinicians must rely on their first-hand experience with needle insertion in combination with tactile sense to successfully identify the location of the vein. This may be a difficult task when attempting to access a small vein in a deep location under the skin, increasing risk of excess pain and/or injury to the patient. There are similar problems with insertion of other invasive medical devices such as guidewires, catheters, introducer needles, stylets, scalpels and guidewires with respect to the inability to precisely visualize the location of the invasive medical device.
Procedural guidance systems utilize a combination of ultrasound and magnetic technologies to provide visualization of subdermal anatomy and device position in the in-plane and out-of-plane orientations. Magnetized needles have been used to guide needle and catheter insertion in conjunction with ultrasound. This combination of ultrasound and magnetic methods also allows for the projection or anticipation of the insertion device position relative to the patient's anatomy, and thereby improves the likelihood of successfully accessing the vasculature and completing the invasive procedure.
The available technology today requires the clinician to manually magnetize the needle in a disposable magnetizer after the removal of the needle from a needle cover just prior to use. The use of needle cover while magnetizing the needle helps to eliminate the accidental damage to the needle tip while maintain the sterility of the device. However, the presence of the needle cover presents a dilemma where the clinicians could not see the needle tip or the length of the needle to be magnetized in most cases. This approach has the potential of resulting in needle tip damage, microbial contamination, and/or inconsistency in the length of magnetized section on the needle. Damage to the needle can occur that is not apparent to the user, which can negatively affect the insertion process. Also, active magnetization of a metal cannula by the user has some limitations and inherent risks, as this approach does not guarantee consistent magnetization since variability in clinician procedures such as depth of insertion, speed of process, and centering of the needle in the magnetizer will result in different degrees of magnetization. The section of the needle near the distal end to be magnetized is the same regardless of actual needle length. However, with a needle cover on the metal cannula, it is difficult for a practitioner to know where the needle is, given that standard needle covers are currently used to cover needles with various lengths. Thus, there is a need to provide visual confirmation to the practitioner for indicating needle penetration depth when the cover is placed into a magnetizer.
Considering the significant risk of needle tip damage, increased potential for contamination and inconsistent magnetization, it would be advantageous to have a system that consistently magnetizes the needle without introducing the aforementioned additional risks. In addition, it is costly to discard the magnetizer after each needle or catheter placement. Thus, there is a need for a device that ensures consistency in the length of the magnetized section of a needle or catheter either with or without a cover covering a portion or the entirety of the tissue-penetrating medical device.